JPH0581606B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention comprises: a unsaturated, crosslinkable thermosetting resin; b ethylenically unsaturated monomer; c reinforcing agent, filler or mixture thereof as additive; and d
This invention relates to a molding composition comprising a normally solid carboxy-containing styrene-butadiene block copolymer. Such compositions are useful, for example, as bulk molding materials (BMCs) or sheet molding materials (SMCs), which naturally exhibit high impact strength, smooth surfaces and low shrinkage/profile properties. . U.S. Pat. No. 4,020,036 describes an unsaturated polyester, a normally solid carboxy-containing styrene-butadiene block copolymer, a vinyl monomer,
A molding composition comprising a catalyst, a reinforcing agent and a filler is disclosed. Although this reference discloses normally solid carboxy-containing styrene-butadiene block copolymers, it does not provide details on how to make these carboxy-containing block copolymers. Furthermore, according to this reference, the vinyl content in the butadiene portion of the block copolymer can vary over a wide range from 5 to 76%. If a carboxy-containing styrene-butadiene block copolymer is prepared in a special way and the 1,2-vinyl content of the butadiene part of the block copolymer corresponds to a certain value, the unsaturated,
A molding composition consisting of a crosslinkable thermosetting resin, an ethylenically unsaturated monomer, a reinforcing agent and/or a filler and a normally solid carboxy-containing styrene-butadiene block copolymer can be
It has now been discovered that, like SMC, it exhibits improved impact strength and improved surface gloss along with low profile/low shrinkage properties. The invention therefore comprises: a. an unsaturated, crosslinkable thermosetting resin; b. an ethylenically unsaturated monomer; c. a reinforcing agent, a filler or a mixture thereof as an additive; and d. a normally solid carboxylic acid. In the molding composition comprising a styrene-butadiene block copolymer containing carboxy-containing styrene-butadiene block copolymer, the carboxy-containing styrene-butadiene block copolymer is heated at a temperature of 20°C to 100°C and 103 kPa (abs) to 793 kPa.
monolithium-terminated styrene-butadiene block copolymer at a pressure of (abs) and a molar ratio of added carbon dioxide to lithium-terminated block copolymer from 0.75:1 to 3.0:1. the butadiene portion of the styrene-butadiene block copolymer prepared by contacting the polymer solution with carbon dioxide by introducing dry gaseous carbon dioxide into the solution and terminated with monolithium; However, before contacting the block copolymer with carbon dioxide, 30 to 40 mol% 1,2-vinyl, 20 to 30 mol%
1,4-cis and 30 to 50 mol% of 1,4
The carboxy-containing styrene-butadiene block copolymer has a trans microstructure and the carboxy-containing styrene-butadiene block copolymer has a 20
~80% by weight uncoupled block copolymer, 10-40% by weight coupled linear block copolymer, and 10-40% by weight 4-armed radial block copolymer at all. The present invention relates to a molding composition as described above, characterized in that it is a mixture of block copolymer structures consisting of no or a small amount of coupled radial block copolymers. An important aspect of the present invention lies in the microstructure of the butadiene block of the styrene-butadiene block copolymer (abbreviated to SB block copolymer).
The microstructure, determined by conventional infrared analysis using the 910 cm ^-1 band, is as follows (expressed in mole %):

[Table] The desired weight average molecular weights of the styrene block and butadiene block of the arms of each block copolymer are as follows.

Table: Carboxy-containing polymers are typically produced by anionic polymerization using organomonolithium initiators. The first step of the process involves contacting the styrene monomer with the organo-monolithium compound in the presence of an inert diluent and adding the active polymeric compound having the simplified structure S-Li to its dilution. This includes producing it in an agent. Inert diluents may be aromatic or naphthenic hydrocarbons, such as benzene or cyclohexane, which may also be modified by the presence of alkenes or alkanes, such as pentene or pentane. Particular examples of suitable diluents include n-pentane, n-hexane, isooctane, cyclohexane, toluene, benzene and xylene. Organo-monolithium compounds are represented by the formula RLi, in which R is an aliphatic compound preferably containing from 2 to 20 carbon atoms in the molecule;
It is an alicyclic or aromatic group or a combination thereof. A highly preferred initiator is secondary butyllithium; by adjusting the concentration of the initiator, the molecular weight of the polymer can be controlled. The concentration of initiator is generally within the above range, although greater and lesser amounts of initiator can be used if desired, from about 0.25 to 50 mmol per 100 grams of monomer. The level of initiator required often depends on the solubility of the initiator in the hydrocarbon diluent. These polymerization reactions are usually carried out at -51℃
to 149° C. and at a pressure sufficient to maintain the reaction mixture in the liquid phase. The active polymer in solution is then contacted with butadiene monomer. The active polymer produced is S-B-
It has a structure simply expressed as Li. Intermediate vinyl polybutadiene blocks are easily obtained by using small amounts of polar substances as vinyl promoters. It is convenient to add the vinyl promoter to the hydrocarbon diluent at an appropriate time during the polymerization sequence. These promoters can be chosen from ethers, tertiary amines and other promoters,
dimethoxybenzene, tetrahydrofuran, 1,
2-dimethoxyethane, dimethyl ether, diethyl ether, methyl ethyl ether, ethyl propyl ether, di-n-propyl ether, di-n-octyl ether, anisole, dibenzyl ether, diphenyl ether, dimethylethylamine, tri-n-propyl amine, tri-n
-butylamine, trimethylamine, triethylamine, N,N-dimethylaniline, N-ethylpiperidine, N-methyl-N-ethylaniline,
N-methylmorpholine and N,N,N',N'-
Tetramethylethylenediamine is preferred. The amount of polar compound used will vary widely depending on the choice of vinyl promoter, but should be that amount necessary to promote the desired degree of vinylation. Typical amount is monomer
It ranges from about 0.01 to 25 parts per 100 parts. The polystyrene content of the polymer is determined by infrared spectroscopy of the finished polymer, whereas the average molecular weight of the polystyrene blocks of the block copolymer is determined by gel permeation chromatography. . After the formation of the butadiene block, the active polymer is contacted with carbon dioxide by introducing dry gaseous carbon dioxide into the active polymer solution. A second important aspect of the invention is that the above contact
carried out at a temperature of 20°C to 100°C and a pressure of 103 to 793 kPa (abs.), and the molar ratio of carbon dioxide to SB-Li added is 0.75:1 to 3.0:1, preferably 1.0:1 to 2.0. : The amount of carbon dioxide is determined so that it becomes 1. Under these circumstances,
20 to 80, preferably 40 to 60% by weight of coupled or uncoupled block copolymers;
40, preferably 15 to 25% by weight of bonded or coupled linear block copolymers and 10 to
A mixture of block copolymer structures consisting of coupled radial block copolymers with a small amount of four-armed radial block copolymers, preferably 25 to 35% by weight, is obtained. Bound or uncoupled block copolymers are probably composed of a mixture of block copolymer structures that differ only with respect to the end groups.
Although carboxylation itself by introducing gaseous carbon dioxide is generally known to those skilled in the art, it is important to note that this carboxylation method produces carboxy-containing styrene-butadiene block copolymers for polyester molding compositions. It has only now been discovered that it is particularly suitable for It will be appreciated that the introduced carbon dioxide can act as both a coupling agent and a carboxylating agent according to the following chemical reaction.

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[Image Omitted] The polymer is then recovered by known finishing methods. Unsaturated, crosslinkable thermoset resins include both unsaturated vinyl ester resins and unsaturated polyester resins. Vinyl ester resins are typically made by esterifying polyepoxides with ethylenically unsaturated monocarboxylic acids in the presence of onium salts of inorganic acids. This vinyl ester resin has the following representative formula,

Produced by reacting glycidyl polyethers of polyhydric phenols with acrylic acid in the presence of onium salts. The composition of the polymerizable unsaturated polyester resin component of the molding compositions of the invention can vary within a wide range. The polymerizable unsaturated polyester portion is usually α,
Produced by reaction with a β-ethylenically unsaturated dicarboxylic acid or a mixture of such acid and a saturated dicarboxylic acid and a dihydric alcohol. Among the ethylenically unsaturated dicarboxylic acids, maleic acid, fumaric acid, mesaconic acid, aconitic acid, citraconic acid, ethylemaleic acid, xeronic acid and itaconic acid can be used. Halogen-substituted derivatives of these acids can also be used. Since the reaction products or polyesters obtained using such acids and their anhydrides are the same, anhydrides of these acids, when present, are included within the term "acid". In fact, it is often preferred to use the anhydride rather than the free acid. The dihydric alcohol components of polyester are ethylene glycol, diethylene glycol, triethylene glycol, polyethylene glycol, 1,
Compounds such as 3-propanediol, 1,2-propanediol, di-1,3-propanediol, butylene glycol and halogen-substituted glycols are included. Small amounts of polyols with functionality greater than 2 may be used with the monovalent component. As previously mentioned, it is often desirable to use small amounts of saturated dicarboxylic acids with the ethylenically unsaturated dicarboxylic acid component. Examples of useful saturated acids include phthalic acid, isophthalic acid, terephthalic acid, succinic acid, adipic acid, suberic acid, azelaic acid, sebacic acid, dimethylsuccinic acid and halogenated derivatives of these acids. The inclusion of saturated dicarboxylic acids as described above in unsaturated polyester resins does not alter the beneficial effects realized from the addition of small amounts of carboxy-containing polymers. Generally, saturated dicarboxylic acids are included as one of the components used in the production of unsaturated polyester resins because the inclusion of such saturated dicarboxylic acids improves certain physical properties. The term "unsaturated polyester resin" as used in the resin industry is interpreted as a resin that uses unsaturated dicarboxylic acids as at least part of the acid component of the polyester; It also includes the resins used. The resulting crosslinkable polyester resins and vinyl ester resins can be easily crosslinked by combining them with ethylenically unsaturated monomers, ie, monomeric compounds containing CH ₂ =C groups. Although many monomers other than styrene and vinyltoluene can be used, styrene and vinyltoluene are most often used as crosslinking monomers, with styrene being the most preferred monomer. Such other monomers include divinylbenzene, ethyl alpha-methylstyrene, chloro- and fluoro-styrene, diallyl phthalate, triallyl cyanurate, allyl diglycolate, diallylphenylphosphonate, diethylene glycol bis(allyl carbonate). , 1,2-propylene glycol bis(allyl carbonate), bis(allyl lactate) carbonate, allyl succinyl allyl glycolate, allyl maleate,
Included are alkyl methacrylates such as methallyl maleate, methyl methacrylate and ethyl methacrylate, alkyl acrylates such as methyl acrylate, ethyl acrylate, propyl acrylate and butyl acrylate, vinyl acetate and allyl acetate. The catalysts used in the present invention are benzoyl peroxide, dicumyl peroxide, methyl ethyl ketone peroxide, lauryl peroxide, cyclohexanone peroxide, tertiary butyl perbenzoate, tertiary butyl hydroperoxide, tertiary butylbenzene cedroperoxide, cumene hydroperoxide. and conventional free radical polymerization initiators selected from organic peroxides and hydroperoxides such as tertiary butyl peroctoate. Additionally, azo compounds such as azobisisobutyronitrile can be used, the currently preferred catalyst being tertiary butyl perbenzoate. The reinforcing agents used in the invention are glass, asbestos, carbon, graphite, metals, synthetic polymers such as polyamides, polyesters, polyolefins and natural fibers such as cotton, jute,
Consists of fibers selected from hemp, sisal, flax, wood, paper and the like. This fiber is matte,
It can be used in the form of fabrics, threads and chopped fibers. Other typical ingredients in sheet and bulk molding materials are viscosity-imparting agents. These thickeners are usually Group metal oxides or hydroxides and specifically include the oxides and hydroxides of magnesium, calcium, strontium, barium and zinc. In addition to the already indicated components of the compositions of the invention, other optional additives can be used, including fillers, pigments, colorants, lubricants, stabilizers and silane coupling agents. ing. Fillers include calcium carbonate, calcium silicate, talc, clay, alumina, aluminum hydroxide, antimony trioxide, silica, mica, barium sulfate, calcium sulfate, and mixtures thereof. Preferred fillers include calcium carbonate, clay, talc and surface treated fillers. aluminum to impart mold release properties to the composition;
Lubricants such as barium, calcium, magnesium or zinc stearates can be used. Conventional colorants and pigments, such as titanium dioxide, carbon black, phthalocyanine pigments and mixtures thereof, can be used in amounts sufficient to impart the desired color to the final molded article. The components are combined by milling techniques with moderate to high shear. This can be accomplished with a twin rotor mixer designed to apply moderate shear forces to the pasty ingredients. It is essential to provide some shear and, due to the viscosity of the materials to be mixed, adequate mixing cannot be obtained by simply stirring or using a conventional impeller mixer. On the other hand, strong mixing should avoid excessive heat (above 35℃)
and activation of the catalyst. Sheet molding compounding line mixing equipment may also be used. This mixing under sufficient shear to achieve good dispersion of each component without accumulating heat and activating the catalyst ensures good formulation and ensures that the carboxyl polymer is normally solid. It requires the fact that it is a substance. 1-50,
Preferably a shear giving a temperature rise of 2 to 30°C is sufficient, and for bulk molding materials low shear is preferred to avoid collapse of the glass. Curing can be accomplished at temperatures known in the art for the particular catalyst used. Generally, 100℃~200℃ in one press
A temperature of 0.degree. C. and a time of 1 to 15 minutes are sufficient. The relative amounts of each component are readily determined and adjusted by those skilled in the art. The relative amounts of the various ingredients are shown below in parts by weight.

Table The invention is further illustrated by the following examples. Example 1 Various bulk molding compositions (BMC) were made with various types of rubber. The formulation of this BMC was as follows (expressed in parts by weight). Ingredients Unsaturated polyester 42 Rubber additives 12 Styrene monomer 46 Glass twine 100 Calcium carbonate 150 Zinc stearate 4 Tertiary butyl perbenzoate (TBPB) 1 Magnesium oxide 2 In this formulation, the polyester used is propylene. It is a glycol-maleate polyester resin. In practice, the polyester was mixed with 18 parts of styrene monomer, while the rubber additive was mixed separately with the remaining 28 parts of styrene monomer. The various ingredients were mixed under standard conditions. next
2 at 175℃ (exothermic peak) and 6894kPa
Each plaque was evaluated by compression molding a plaque from each component for minutes and then measuring its physical properties. All rubber components used in the bulk molding compositions are based on styrene-butadiene block copolymers made from alkyl lithiums. Three of the polymers are diblocks (block copolymers 1, 9 and 10) with no bonding or coupling, and one of them (block copolymer 9) has a high vinyl content in the butadiene moiety. However, other polymers are bound or coupled with various coupling agents.
The degree of coupling is shown in Table 1 by reference to the various types - SB ₁ , SB ₂ , SB ₃ , SB ₄ .
For example, SB ₂ refers to a type of polymer with the SB-X-SB structure, while SB ₃

[Formula] means a type of polymer having the structure, where X is a coupling residue. Some of the polymers were combined or reacted with carbon dioxide. These are copolymers 7, 8 and 1
It is 1. Only block copolymer 7 is according to the invention, and the 1,2-vinyl content of the butadiene moiety in the other two polymers is too low. A description of the polymers and impact values (undescored Izod measured by ASTM 256) is given in Table 1.

Table: Examples Two different sheet molding compositions (SMC) were made from two different rubbers. One rubber was block copolymer 11 and the other rubber was a polymer of the invention represented by block copolymer 12. Block copolymer 12 was prepared by 1) polymerizing 8154 g of styrene in the presence of 479.3 ml of secondary butyllithium in 73,386 g of cyclohexane at 50° C. for 15 minutes; 2) in the presence of 114,880 g of cyclohexane.
An active styrene-butadiene block copolymer was prepared by polymerizing 22,831 g of butadiene and 43,488 g of the solution obtained in step 1) in the presence of 16.75 ml of orthodimethoxybenzene; 3) the polymer solution; 16g of gaseous carbon dioxide is introduced for 15 minutes below the surface of the
and 4) terminating the reaction with 20 ml of methanol. A comparison between the two polymers is shown in Table 2.

Table: Two rubbers were used in the same sheet molding composition formulation. The formulation had the following ingredients (expressed in parts by weight): SMC Formulation Unsaturated Polyester Resin Solution 420 Rubber 126 Styrene Monomer 294 TBPB 9 Pigments 3 Zinc Stearate 39 Calcium Carbonate 1260 Magnesium Oxide 21 Glass Fiber 840 Total 3011 Approximately 300 lbs of each formulation per standard conditions was manufactured. A portion of this sheet molding composition was then compression molded into flat plaques and the plaques were analyzed by standard tests. The results of these tests are shown in Table 3.

【table】

[Table] Physical properties were determined according to the following test procedure. Flexural Modulus and Strength, ASTM D790 Tensile Strength and Elongation, ASTM D256 Shrinkage, ASTM D955 Hardness, Barcol Additionally, truck doors were made from the sheet molding compositions. The results are shown in Table 4 below.

Table: The doors made with the sheet molding composition according to the invention not only had the most favorable balance of properties, but also had the best surface appearance.

Claims (1)

[Scope of Claims] 1 a. an unsaturated, crosslinkable thermosetting resin; b. an ethylenically unsaturated monomer; c. a reinforcing agent, a filler or a mixture thereof as an additive; and d. a normally solid carboxy-containing compound. In a molding composition comprising a styrene-butadiene block copolymer, (i) the carboxy-containing styrene-butadiene block copolymer is heated at a temperature of 20°C to 100°C;
Pressure from 103 kPa (absolute) to 793 kPa (absolute) and molar ratio of carbon dioxide added to lithium-terminated block copolymer.
Contacting the monolithium terminated styrene-butadiene block copolymer solution with carbon dioxide by introducing dry gaseous carbon dioxide into the solution at a ratio of 0.75:1 to 3.0:1. (ii) the monolithium-terminated styrene-butadiene block copolymer has a butadiene moiety of 30 to 40 mole % before contacting the block copolymer with carbon dioxide; 1,
2-vinyl, has a microstructure of 20 to 30 mol% 1,4-cis and 30 to 50 mol% 1,4-trans, and (iii) the carboxy-containing styrene-butadiene block copolymer has 20-80% by weight uncoupled block copolymer, 10-40% by weight coupled linear block copolymer and 10-40% by weight four-armed radial block copolymer. The above-mentioned molding composition is characterized in that it is a mixture of block copolymer structures consisting of either no or a small amount of coupled radial block copolymers. 2. Claims for the production of normally solid carboxy-containing block copolymers at a molar ratio of carbon dioxide added to lithium-terminated block copolymers of 1.0:1 to 2.0:1. The composition according to item 1. 3. The thermosetting resin is a polyester resin.
A composition according to claim 1. 4. The composition of claim 3, wherein the polyester resin is produced by the reaction of an unsaturated dicarboxylic acid and a polyol. 5. The composition according to claim 1 or 3, wherein the unsaturated monomer is styrene. 6. The composition of claim 1, wherein the additive is calcium carbonate. 7. The composition of claim 1, wherein the additive is a mixture of calcium carbonate and chopped glass fibers. 8. Composition according to claim 1, wherein the molding composition additionally comprises a catalyst. 9. The composition of claim 8, wherein the catalyst is an organic peroxide. 10 The weight average molecular weight of each styrene block in the block copolymer before reaction with carbon dioxide is 8,000 to 20,000, and the weight average molecular weight of each butadiene block in the block copolymer before reaction with carbon dioxide is 30000 or so
100,000.